The Koh-i-Noor was a massive diamond that has a long and mostly mysterious hystory. There are a few versions of its past, some being that it was sifted out of sand, some that it is cursed and revered by many Indian deities. It was worn by many rulers all throughout India and Asia. It is most controversial because it now adorns the crown jewels in England despite the Indian, Pakistani, Iranian, and Afghanistanian governments having claimed its ownership. The story is that it was taken during the annexation of India by Britian. Queen Victoria was given the diamond when the Treaty of Lahore was signed, "The gem called the Koh-i-Noor, which was taken from Shah Sooja-ool-moolk by Maharajah Ranjeet Singh, shall be surrendered by the Maharajah of Lahore to the Queen of England (sic)"

It was worn as a brooch by Queen Victoria and was even put on display at the Great Exhibition in London, but people weren't impressed by the diamonds appearance. Prince Albert had it recut which shaved down quite a bit of its size. It currently resides on the crown that is worn during corronations.

***The image attached is a replica***
Works cited: https://www.smithsonianmag.com/history/true-story-koh-i-noor-diamondand-...
https://www.britannica.com/topic/Koh-i-noor